Waterproof connectors often use a wire seal or seal member, known as a family seal, disposed in a connector housing to prevent water and the like from penetrating from the outside. This wire seal comprises a plurality of wire insertion passageways at positions corresponding to a plurality of contacts (terminal fittings) held by the connector housing. When the contact is inserted into a cavity for holding the contact through the wire insertion passageway, an electric wire connected to the contact comes into tight contact with a seal projection provided around the wire insertion passageway, thereby ensuring the waterproofness of the connector.
However, in cases involving a waterproof connector having a wire seal with plurality of wire insertion passageways of the same specifications, contacts having electric wires with different wire diameters are often inserted. When a thick electric wire is inserted into the wire insertion passageway, the compressed seal material has no escape space in the surroundings of the wire insertion passageway, so the seal material runs off into the adjacent wire insertion passageway. In this case, if an attempt is made to insert a thick electric wire into the adjacent wire insertion passageway, the running-off seal material becomes a resistance, and the burden of contact-mounting work increases. If an attempt is made to insert the thick electric wire forcibly, a rubber break occurs in the seal material (seal projection). In this case, the desired waterproofing performance cannot be achieved.
To combat the above-described problems, some proposals have been made (for example, Japanese Patent Publication No. 2005-317385 and Japanese Patent Publication No. 2010-140876).
Japanese Patent Publication No. 2005-317385 proposes a technique in which relief grooves depressed in the thickness direction of a seal member are formed at positions adjacent to the wire insertion passageways near the outer edge of wire seal. However, since the relief grooves are provided near the outer edge of the wire seal, although the seal material located on the outer periphery side of the wire seal can run off into the relief grooves, the seal material located at positions distant from the outer periphery side cannot run off into the relief grooves.
Japanese Patent Publication No. 2010-140876 proposes a technique in which one side in the axial direction of the wire insertion passageway provided in the wire seal is made a large-diameter section, and the other side thereof is made a small-diameter section, and the adjacent wire insertion passageways are arranged so that the orientations of the large-diameter section and the small-diameter section are different between the front surface and the back surface of the seal member. However, where the small-diameter section of the wire insertion passageway is arranged on the contact insertion side, the contact abuts with the seal material around the small-diameter section, so that contact insertion requires greater insertion force, and, a rubber break may occur if an attempt is made to insert the contact forcibly.
Accordingly, an object of the invention, among other objects is to provide a wire seal into which even an electric wire having a large wire diameter can be inserted without difficulty, and without depending on the position at which a wire insertion passageway is arranged.
Also, another object of the invention is to provide a waterproof connector comprising the above-described wire seal to achieve the desired waterproofing performance.